Table 5. Risk Groups within Derivation and Validation Cohort.

Risk Group	Score*	Derivation Cohort	Validation Cohort
Low	1–5	13/529 (2.5)	1/135 (0.7)
Intermediate	6–10	36/305 (11.8)	6/82 (7.3)
High	10–16	43/126 (34.1)	8/19 (42.1)

^*Sum of scores for each variable as shown in Table 4.